For all but the ambidextrous, having a dominant hand is simply a matter of course. However, most people also have a dominant eye and are unaware of it. This is called ocular dominance (also sometimes called eye dominance). Knowing your dominant eye is helpful in a variety of places and situations.

To determine which of your eyes is dominant, start with Step 1 below
How to perform a Standard Blink Test
(a.k.a. the Miles Test)

Step 1:Hold your hands at arm’s length out in front of you. Your palms should be pointing forward.(in other words, you should be looking at the backs of your hands.)

Step 2:Make a “triangle.” Extend both of your thumbs so that they’re roughly perpendicular to the rest of the hand. Overlap your hands so that the space between makes a triangle. Your two thumbs should be at the bottom of the triangle, while the edge and index finger of each hand form the two remaining sides.

(The triangle space between your hands acts as a viewing window – you should be able to clearly see objects through it.)

Step 3:Look at an object through the triangle hole made by your hands with both eyes open. Find a nearby object that’s small enough (or far enough away) that you can see the whole object through the viewing window between your hands. This can be anything – a doorknob, a coffee mug, or even a letter on a faraway billboard.

Step 4:Focus on the object. Try to focus your eyes on the object between your hands – not your hands themselves. Your hands should become somewhat blurry, while the object remains clear and in-focus. It’s important to line this object up directly in front of you and to stare straight at it. (turning your head to either side can distort your results).

(For best results, at this point, make minor adjustments to your hands so that the object you’re looking at fits almost exactly within the edges your viewing window. In other words, if your triangle is bigger than the object you’re looking at, move your hands together to make it smaller, and vice versa).

Step 5:Alternate closing each eye to see which gives better vision. Close one eye, then open it and close the other. Each time you switch eyes, the object you’re looking at should do one of two things. It should either become obscured behind one of your hands or remain visible. Your dominant eye is the one that allows you to see the object while it remains open.

(example: if you close your left eye and the object jumps out of your vision, but you close your right eye and the object stays stationary, your left eye is your dominant eye).

– Though it is rare, it is possible for someone to exhibit ambidexterity in their eyes – in other words, for both eyes to be equally dominant.

Step 6:Results: Which of your eyes is dominant?

You should now know which of your eyes is dominant. It’s either Right or Left.